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Feb, 1938
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Oct, 1938
THIS THING CALLED LIGHTNING
Storm phenomena that have puzzled scientists for generations solved by laboratory methods and experiments with man-made lightning. WHY are some flashes of lightning not accompanied by thunder? Why, when lightning reaches the ground, does it sometimes emerge and cause more damage? These are some of the questions about the most puzzling of natural phenomena that have yielded to exhaustive experiments and study in the open and in the laboratory.
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Black Light and the Criminal
Ultra-violet rays, now readily accessible to law enforcing bodies, adds another weapon to the arsenal of the government's war on lawlessness. THE use of filtered ultra-violet light for crime detection and identification purposes has been made available by the presentation of a comparatively low cost, yet powerful, efficient and portable black-ray quartz lamp. Specially formulated dark-colored Wood's glass filters in the front of lamp hold back the visible light emitted by the mercury arc and allow only a concentrated beam of invisible ultra-violet, or "black light," to pass. This ray cannot be seen by the eye, even in the dark or semi-dark, yet its radiations are absorbed by a wide variety of substances and instantly re-emitted as visible light of constant intensity and color.
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